Many businesses and other enterprises currently desire to include and recognize internal and external parties in their network. The inclusion and recognition of internal parties is relatively easy as there is usually a high degree of trust between the internal party and the enterprise. Trust between an external party and the enterprise, however, is not as well established. The difficulty with this situation is that the enterprise may desire to provide services to the external party similar to services made available to internal parties and the external party may desire to access such features as easily as an internal party. The main problem encountered by many enterprises is the need to balance the desire to provide useful and possibly new services to internal and external parties while preserving the security of the enterprise and parties involved in the interaction.
For several years the world's communication SPs (Service Providers) have been working with the 3GPP (3rd Generation Partnership Project) to create a set of interoperable standards to provide voice, video, and data services to their subscribers based on SIP (Session Initiation Protocol), the underlying protocol of IMS (IP Multimedia Subsystem).
The IMS standards allow SP's the ability to expose applications and services to their users independent of the communication device being used by the user. Currently, there is no way to extend or coordinate these applications and services (such as multiple applications/services that operate on the same call—i.e. sequenced applications) within an SP domain to users that are only identifiable in a different domain (e.g., an enterprise domain). Providing common services would lower the total cost of ownership because the cost could be internalized, ease deployment of new services to a larger community, and provide better coordinated services to a larger unexpected community of users despite the device used.
The identified hurdles include the following: (a) the connection between the SP and an enterprise are not secure; (b) there is no association between a user in the SP domain with the enterprise domain; (c) there is no way to expose enterprise features and services to users in the SP domain; (d) there are limited modes of communication between domains; (e) the authentication between a user and the SP domain is meaningless in the enterprise domain; and (f) Session Border Controllers and the transport provider (the companies that carry the messages between the two Session Border Controllers) often strip out information from the messages that are being transported either for security reasons or because they simply are not knowledgeable about what the information is and, therefore, decide to remove it.
One proposed solution to the above-noted problem has been developed by Tango Networks and is called Abrazo. Abrazo provides for mobile phone association (“twinning” or otherwise known as “Extension to Cellular”) of the mobile phone identity in the SP IMS network to the internal identity in an enterprise IMS network. In this solution, each mobile phone user has two extensions associated with the user. A first extension which the PBX owns and is the primary extension in the enterprise. A second extension which is on the Abrazo server and is the extension that is twinned/mapped to the first extension. This solution is disadvantageous because twice as many licenses are required to be paid to Abrazo for the use of their system. A pilot number is used to route calls from the mobile operator network (SP) into the enterprise and ultimately to the Abrazo server. As can be appreciated by one skilled in the art, this is a somewhat costly and cumbersome solution.